macro_rules! const_for { (($i:ident in $start:tt..$end:tt) $code:expr ) => { ... }; }
Expand description
A helper macro for emulating for
loops in a const
context.
Usage
const fn for_in_const() {
let mut array = [0usize; 4];
const_for!((i in 0..(array.len())) { // We need to wrap the `array.len()` in parenthesis.
array[i] = i;
});
assert!(array[0] == 0);
assert!(array[1] == 1);
assert!(array[2] == 2);
assert!(array[3] == 3);
}